Darren E. Nisly, D.O. FACS
General Surgeons of Western Colorado
Dr. Nisly graduated from medical school at Rocky Vista University in Colorado and completed his General Surgery residency at Henry Ford Allegiance in association with Michigan State University. He is board certified in General Surgery and a Fellow of the American College of Surgeons.
Trained in the era of robotics he is experienced in abdominal wall reconstruction and general abdominal surgery using the DaVinci robotic platform; a technology Grand River Hospital is proud to offer beginning in January of 2026.
Raised in a remote town in Ontario Canada, he has a special interest in delivering quality surgical services to small communities. In keeping with this interest, he completed an honors track in Rural and Wilderness Medicine and regularly participates in surgical missions to Central America.
Darren E. Nisly, D.O. FACS
General Surgeons of Western Colorado Dr. Nisly graduated from medical…
Steven O’Day, MD
General Surgeons of Western Colorado
Dr. O’Day graduated from Creighton University School of Medicine and completed his residency in General Surgery at Exempla St. Joseph Hospital in Denver, Colorado. He is licensed by the State Board and Certified by the American Board of Surgery. He is a member of the American College of Surgeons, The Mesa County Medical Society, and Southwestern Surgical Congress.
Education
- Creighton University School of Medicine Omaha, Nebraska, Doctor of Medicine
- University of Colorado, Boulder, Colorado, Bachelor of Arts in Kinesiology
Certifications
- Certified by the American Board of General Surgery
Steven O’Day, MD
General Surgeons of Western Colorado Dr. O’Day graduated from Creighton…
Alero Nanna, MD
General Surgeons of Western Colorado
Dr. Alero Nanna graduated from Howard University College of Medicine in 2009. There she completed the very competitive accelerated BS/MD program, with the prestigious Presidential scholarship. She proceeded to complete her residency in General Surgery at Mount Sinai Hospital in New York City in 2014. After completing residency, she worked in underserved areas in South Arkansas where she was a general surgery attending for three years. Dr. Nanna is Board Certified by the American Board of Surgery and licensed by the Colorado Medical Board. Dr. Nanna joined us in Rifle in January 2018.
Alero Nanna, MD
General Surgeons of Western Colorado Dr. Alero Nanna graduated from…
Craig Andersen, MD, FACS
General Surgeons of Western Colorado
Dr. Andersen graduated from Harvard University School of Medicine and completed his Residency in General Surgery at the University of Colorado Health Sciences Center in 1996. He is licensed by the Colorado State Board and certified by the American Board of Surgery. He is a member of the Mesa County Medical Society and the Colorado Medical Society. Dr. Andersen has been practicing in Grand Junction since 1996, and joined Grand River Health in 2016.
Education
- University of Colorado Health Sciences Center – Residency in General Surgery
- Harvard Medical School
- Doctor of Medicine University of Rochester – Bachelor of Science
Certifications
- Certified by the American Board of Surgery
- Professional Orgnizations
- Colorado Medical Society
- Mesa County Medical Society
Craig Andersen, MD, FACS
General Surgeons of Western Colorado Dr. Andersen graduated from Harvard…
Caleb Van Essen, MD
General Surgeons of Western Colorado Dr. Essen’s medical training includes…
Douglas Hirth, MD
General Surgeons of Western Colorado Dr. Hirth graduated from State…
Eric Hanly, MD
General Surgeons of Western Colorado Dr. Hanly attended medical school…
Joel Schaefer, MD FACS
General Surgeons of Western Colorado Dr. Schaefer graduated from the…
Joyce Sekharan, MD FACS
General Surgeons of Western Colorado Dr. Sekharan’s most recent practice…
Kristen Ohe, MD
General Surgeons of Western Colorado Kristen Ohe, MD is a…
Leonard K. Welsh, MD, FACS, FASMBS
General Surgeons of Western Colorado A native of central California,…
Tanner Spees, MD
General Surgeons of Western Colorado Education St. Georges University School…
Teyen Shiao, MD
General Surgeons of Western Colorado Dr. Shaio graduated from University…